Need help on some physics~

[TecHNooB]

The original question was posted here:
http://forums.anandtech.com/messageview.aspx?catid=38&threadid=1933223

I just got a conceptual question. Again, the question is based on fission. After I find the energy through the difference in mass before and after the reaction, how do I go about finding the velocity of the particles?

 

[Born2bwire]

F=ma.

EDIT: Looking back over it quickly, using the repulsion force seems like you would need to work backwards through the problem. Since you can assume a non-relativistic system, then I would just use the classical kinetic energy relationship.